Copas is a dispatcher based on coroutines that can be used by TCP/IP
socket request/response servers. It uses LuaSocket as the interface with
the TCP/IP stack.

A server registered with Copas should provide a handler for requests and
use Copas socket functions to send the response. Copas loops through
requests and invokes the corresponding handlers.

Since Copas is coroutine based, using it within a pcall or xpcall context
does not work with Lua 5.1 yielding. If you need to use those functions
we strongly suggest using Xavante's coxpcall, a coroutine safe version
of the Lua 5.1 protected calls.
